Banca de DEFESA: FERNANDA MONICELLI CAMARA BRITO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FERNANDA MONICELLI CAMARA BRITO
DATE: 07/02/2020
TIME: 09:00
LOCAL: Sala de videoconferência do PoP/RN - Localizada no Centro de Convivência da UFRN
TITLE:

Potential phosphorus sorption by natural adsobents materials from the semiarid for eutrophication control

KEY WORDS:

Precipitation. Adsorption. Langmuir. Humic substances. pH.

 

PAGES: 38
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUMMARY:

Internal loading phosphorus has been identified as the main cause of maintaining the eutrophic state of eutrophic lakes even though reduction of external loads. Thus, the mitigation of eutrophication of these systems through the geoengineering technique has been an alternative due to the manipulation of phosphorus biogeochemical cycle, immobilizing it through sorption. Sorption is a process that mainly includes adsorption and precipitation. For this, natural materials, such as clays, have been tested, showing promising and lower cost results. The goals of this work was to evaluate the phosphate sorption potential of three natural adsorbents (Luvissolo, Scheelita Reject and Planossolo), comparing with a commercial adsorbent, lanthanum modified bentonite (BML); test the effect of pH and humic substances on phosphate sorption. Physical, chemical and mineralogical analyzes of the adsorbents were made and after that adsorption tests, under controlled conditions of pH 6, 8 and 10. Luvissolo and Planossolo were incinerated to reduce the humic substances. The results were placed in the Langmuir and Freundlich models. Only Scheelita Reject, Planossolo and BML increased the pH of the water. The Reject and Planossolo obtained the highest percentages of removal, with values around 40 to 60% up to 20 mg L-1. Langmuir's isotherm was suitable for all adsorbents, whereas Freundlich's isotherm was only for natural ones. Reject was the natural adsorbent that obtained the highest maximum adsorption capacity (Q), 8.5 mg L^-1, followed by Planossolo, 7.8 mg L^-1, both obtained higher values of Q at pH 8. All results from Luvissolo and other natural adsorbents only under pH 10 were not statistically significant. After treatment to reduce humic substances, Planossolo started to have a Q of 24.1 mg g^-1, while the Luvissolo remained non-significant. The sorption potential was satisfactory in the natural adsorbents, being higher at pH 8 due to the precipitation process that was more expressive than the adsorption, where the Reject and Planossolo were better among the natural ones. The reduction of humic substances potentiated the sorption process, mainly in the Planossolo. The cations of the sorting complex (Ca²⁺, Mg²⁺, K⁺, Na⁺, H⁺) and the mineralogy of the adsorbent materials were important characteristics to understand the sorption process.

BANKING MEMBERS:
Externa à Instituição - MAÍRA NUNES TEIXEIRA MUCCI - WAUNI
Externo à Instituição - JOSÉ NEUCIANO PINHEIRO DE OLIVEIRA - IFCE
Interna - 1662859 - KARINA PATRICIA VIEIRA DA CUNHA
Presidente - 1764855 - VANESSA BECKER